"Why, the fire, of course."
"How long will the stove stay hot?"
"As long as there is fire in it."
"Longer than that," said Donald. "It doesn't grow cold the minute the fire is out."
"What becomes of all the heat?" asked Uncle Robert.
"Oh, it goes all round the room."
"Let's put the thermometer in the hot water," said Susie.
"Oh, see it go up!" said Donald. "It is one hundred and fifteen already."
"What is the difference in degrees between the cold and the hot water?" asked Uncle Robert.
"Sixty-seven degrees," said Frank.